Ensuring optimal plant nutrition requires a well-structured approach, precise monitoring, and the right tools.
During the Nutrient Know-How Talk at the Indoor Ag-Con, host Michelle Keller of Living Greens Farm led an insightful discussion with Dr. Cari Peters of JR Peters, Randy Nester of Anderson Injectors, and Fallon Lowe of Bright Farms. The experts shared practical strategies for balancing fertilizer costs while maximizing yield, identifying nutrient imbalances, and refining best practices in crop nutrition.
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Consistency and monitoring when it comes to nutrients
Fallon emphasizes that operational consistency is crucial in optimizing nutrient application. "Unforced errors happen frequently, so having good procedures in place is essential." Randy agrees, highlighting the importance of setting clear goals. "Know what you want to achieve for your plants. Make a standard operating procedure (SOP) and follow through."
Dr. Cari provides insight into JR Peters' evolution from handshake fertilizer deals to precise lab-controlled nutrient management. "We monitor every detail down to the correct frequencies and amounts," she says, stressing that even minor imbalances in macro- and micronutrients can impact plant health. "Know your sensors; understand what you're dealing with," Randy adds.
For crops with short cycles like lettuce, frequent sampling is vital. "We need to know what's happening every week in our 21-day crop cycle," Fallon explains. "Some deficiencies, like tip burn, are visible, but others require lab analysis. Get to know your frequencies and exactly what you need."
Avoiding common mistakes
One frequent mistake growers make is neglecting equipment calibration. "Incorrect readings can lead to wrong decisions," Randy warns. Fallon points out that many errors stem from incorrect product mixing. "I've seen a lot of mistakes at the injection point—mixing the wrong products or making decisions based on false assumptions. It's essential to identify the root cause before reacting."
Michelle asked how growers should respond to high electrical conductivity (EC) levels. Dr. Cari advises first checking the formulation. "Ensure the mix is correct and that the right tank is being used." Randy adds, "The first step is to bring the EC down—dilution is the solution to your grower's pollution," referencing Michelle's phrase. Fallon emphasizes sensor accuracy, noting that an incorrect reading can lead to unnecessary corrective actions.
Best practices for nutrient management
Randy encouraged growers to stick to a structured approach. "Stay on top of your process. Start with a plan, follow it through, and check the results. Avoid changing more than one variable at a time." Fallon suggests the 80-20 rule: "Focus on the simplest solution that will get you 80% of the way to your target. Then refine the last 20%."
Understanding water quality is a crucial first step. "Know your water source," Dr. Cari stresses. "Test for pH, alkalinity, and existing nutrient content before adding anything. Some sources already contain beneficial elements like calcium, while others have excess boron, which can be problematic." Fallon points out that water quality fluctuates seasonally. "In summer, water might get too hot, affecting nutrient uptake. Regular testing helps adjust for these changes."
Tissue sampling is another essential tool. "Problems can be variety-specific," Fallon notes. "No single formula works for all varieties." For short-cycle crops like lettuce, proactive nutrient management is key. "Since issues appear quickly, we must address them before the next crop cycle."
Comprehensive testing and environmental considerations
Testing should be conducted at multiple points within the system. "Analyze water from the roots, irrigation units, and throughout the process," Randy advises. "If discrepancies appear between samples, test further until the issue is identified—it could be something like biofilm buildup blocking nutrient absorption."
Dr. Cari cautions against excessive testing without a clear action plan. "Testing is expensive, so be ready to analyze and act on the results." Fallon adds that nutrient uptake varies depending on the crop stage. "Potassium, for example, is absorbed rapidly during fast growth but slows down later. Overapplying at the wrong stage is wasteful."
Rather than being overwhelmed by multiple data sets, growers should establish a reliable range of values for their system. "Regular spot-checking within an optimal range is more effective than trying to micromanage every fluctuation," Dr. Cari explains.
Nutrient management should integrate with biological systems. "High-quality products support both plants and beneficial microbes," Dr. Cari notes. "Decide on the right nutrients and injector system, then replicate the process daily so you can focus on optimizing other aspects of your operation."
The bigger picture
Fallon urged growers to consider the entire growing environment. "Even if you're supplying nutrients, factors like light intensity, humidity, pH, and temperature affect uptake."
Hydroponic systems, while soil-free, still require biological care. "Dissolved oxygen for example plays a vital role in establishing beneficial biologicals," Fallon emphasizes.
With structured monitoring, proper calibration, and a holistic approach, nutrient management becomes a more predictable and efficient process. As Fallon summarizes, "By making informed, strategic adjustments, growers can maximize yields while keeping nutrient costs in check."